Parallel execution

After having completed the domain decomposition via the decomposePar utility, the following commands does the same actions, where process is intended either as solver or mesher:

# 1st
mpirun -np <\cores\> <\solver\> -parallel > iterations.log &
# 2nd - equivalent commands
foamJob -parallel <\solver\>

To take full advantage of the hardware, use the maximum number of physical cores, remember to disable the hyperthreading on the machine you are running. The output of the previous command writes a log file that records either events that occur in the machine to monitor the simulation.

#Live scrolling
tail -f  iteration.log
# Static scrolling
tail -<\linesToDisplay\>       

When the simulation is finished, all you time-step/iteration are in the processor’s folder, to build a single case the following command it is needed:

reconstructParMesh
reconstructPar

If you need to kill the process in parallel, check top at first and the execute:

pkill <\processName\>

if for some reason the process does not close, given the fact OpenFOAM® processes are not vital for the system you can force the kill using :

kill -9

Parallelization issues

Given the case the 0 directory has not been set before the case decomposition, what you can recover the mesh reconstructing it and then decompose it again with annex the 0 folder in place following this series of command at meshing done::

reconstructParMesh -constant
restore0Dir
decomposePar -force

When it is reconstructed only the mesh, and decomposed a second time to include the 0 directory, an error can occur when trying to reconstruct at the conclusion of the case. A solution is to run:

reconstructParMesh -constant && reconstructPar -latestTime